For any communication via public land mobile networks, operators have the legal obligation to provide means for lawful interception towards the national authorities. Normally, the network provides a special lawful interception interface which allows breaking out traffic towards and from terminal devices which are subject to lawful interception. The details of the lawful interception requirements, lawful interception architecture and lawful interception interfaces are defined by 3GPP in TS 33.106, TS 33.107 & TS 33.108. In 3GPP the interface is called “Handover interface for lawful interception”. Depending on the service domain (Circuit Switched vs. packet switched), the interfaces for traffic being forwarded to the lawful interception interface originate in the MSC (Mobile Switching Center), e.g. for CS voice traffic, or in the GGSN (GPRS (Global Packet Radio System) Gateway Support Node), e.g. for packet data services.